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Journal articles on the topic 'Marine Ice sheet'

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1

HASELOFF, MARIANNE, and OLGA V. SERGIENKO. "The effect of buttressing on grounding line dynamics." Journal of Glaciology 64, no. 245 (2018): 417–31. http://dx.doi.org/10.1017/jog.2018.30.

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ABSTRACTDetermining the position and stability of the grounding line of a marine ice sheet is a major challenge for ice-sheet models. Here, we investigate the role of lateral shear and ice-shelf buttressing in grounding line dynamics by extending an existing boundary layer theory to laterally confined marine ice sheets. We derive an analytic expression for the ice flux at the grounding line of confined marine ice sheets that depends on both local bed properties and non-local ice-shelf properties. Application of these results to a laterally confined version of the MISMIP 1a experiment shows tha
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2

Gandy, Niall, Lauren J. Gregoire, Jeremy C. Ely, et al. "Marine ice sheet instability and ice shelf buttressing of the Minch Ice Stream, northwest Scotland." Cryosphere 12, no. 11 (2018): 3635–51. http://dx.doi.org/10.5194/tc-12-3635-2018.

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Abstract. Uncertainties in future sea level projections are dominated by our limited understanding of the dynamical processes that control instabilities of marine ice sheets. The last deglaciation of the British–Irish Ice Sheet offers a valuable example to examine these processes. The Minch Ice Stream, which drained a large proportion of ice from the northwest sector of the British–Irish Ice Sheet during the last deglaciation, is constrained with abundant empirical data which can be used to inform, validate, and analyse numerical ice sheet simulations. We use BISICLES, a higher-order ice sheet
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3

Mulder, T. E., S. Baars, F. W. Wubs, and H. A. Dijkstra. "Stochastic marine ice sheet variability." Journal of Fluid Mechanics 843 (March 23, 2018): 748–77. http://dx.doi.org/10.1017/jfm.2018.148.

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It is well known that deterministic two-dimensional marine ice sheets can only be stable if the grounding line is positioned at a sufficiently steep, downward sloping bedrock. When bedrock conditions favour instabilities, multiple stable ice sheet profiles may occur. Here, we employ continuation techniques to examine the sensitivity of a two-dimensional marine ice sheet to stochastic noise representing short time scale variability, either in the accumulation rate or in the sea level height. We find that in unique regimes, the position of the grounding line is most sensitive to noise in the acc
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4

Pegler, Samuel S. "Suppression of marine ice sheet instability." Journal of Fluid Mechanics 857 (October 25, 2018): 648–80. http://dx.doi.org/10.1017/jfm.2018.742.

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A long-standing open question in glaciology concerns the propensity for ice sheets that lie predominantly submerged in the ocean (marine ice sheets) to destabilise under buoyancy. This paper addresses the processes by which a buoyancy-driven mechanism for the retreat and ultimate collapse of such ice sheets – the marine ice sheet instability – is suppressed by lateral stresses acting on its floating component (the ice shelf). The key results are to demonstrate the transition between a mode of stable (easily reversible) retreat along a stable steady-state branch created by ice-shelf buttressing
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5

Schoof, Christian. "Marine ice sheet stability." Journal of Fluid Mechanics 698 (March 15, 2012): 62–72. http://dx.doi.org/10.1017/jfm.2012.43.

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AbstractWe examine the stability of two-dimensional marine ice sheets in steady state. The dynamics of marine ice sheets is described by a viscous thin-film model with two Stefan-type boundary conditions at the moving boundary or ‘grounding line’ that marks the transition from grounded to floating ice. One of these boundary conditions constrains ice thickness to be at a local critical value for flotation, which depends on depth to bedrock at the grounding line. The other condition sets ice flux as a function of ice thickness at the grounding line. Depending on the shape of the bedrock, multipl
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6

Pegler, Samuel S. "Marine ice sheet dynamics: the impacts of ice-shelf buttressing." Journal of Fluid Mechanics 857 (October 25, 2018): 605–47. http://dx.doi.org/10.1017/jfm.2018.741.

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Marine ice sheets are continent-scale glacial masses that lie partially submerged in the ocean, as applies to significant regions of Antarctica and Greenland. Such ice sheets have the potential to destabilise under a buoyancy-driven instability mechanism, with considerable implications for future sea level. This paper and its companion present a theoretical analysis of marine ice sheet dynamics under the effect of a potentially dominant control of the buttressing force generated by lateral stresses on the downstream floating component of the ice sheet (the ice shelf). The analysis reveals crit
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7

Meur, E. Le, and Richard C. A. Hindmarsh. "Coupled marine-ice-sheet/Earth dynamics using a dynamically consistent ice-sheet model and a self-gravitating viscous Earth model." Journal of Glaciology 47, no. 157 (2001): 258–70. http://dx.doi.org/10.3189/172756501781832322.

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AbstractWe use a self-gravitating viscoelastic model of the Earth and a dynamically consistent marine ice-sheet model to study the relationships between marine ice-sheet dynamics, relative sea level, basal topography and bedrock dynamics. Our main conclusion is that sea-level change and lithospheric coupling are likely to have played limited roles in the postglacial retreat of marine ice sheets. The postglacial rise in sea level would only have caused at the most around 100 km of grounding-line retreat for an ice sheet of similar dimensions to the West Antarctic ice sheet, compared with the se
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8

Zweck, Chris, and Philippe Huybrechts. "Modeling the marine extent of Northern Hemisphere ice sheets during the last glacial cycle." Annals of Glaciology 37 (2003): 173–80. http://dx.doi.org/10.3189/172756403781815870.

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AbstractMechanisms that determine time-dependent changes of the marine ice margin in dynamic ice-sheet models are important but poorly understood. Here we derive an empirical formulation for changes in the marine extent when modelling the Northern Hemisphere ice sheets over the last glacial cycle in a three-dimensional thermomechanically coupled ice-sheet model. We assume that the strongest control on changes in marine extent is ice calving, and that the variable most crucial to calving is water depth. The empirical marine-extent relationship is tuned so that the major marine-retreat history o
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9

Tsai, Victor C., Andrew L. Stewart, and Andrew F. Thompson. "Marine ice-sheet profiles and stability under Coulomb basal conditions." Journal of Glaciology 61, no. 226 (2015): 205–15. http://dx.doi.org/10.3189/2015jog14j221.

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AbstractThe behavior of marine-terminating ice sheets, such as the West Antarctic ice sheet, is of interest due to the possibility of rapid grounding-line retreat and consequent catastrophic loss of ice. Critical to modeling this behavior is a choice of basal rheology, where the most popular approach is to relate the ice-sheet velocity to a power-law function of basal stress. Recent experiments, however, suggest that near-grounding line tills exhibit Coulomb friction behavior. Here we address how Coulomb conditions modify ice-sheet profiles and stability criteria. The basal rheology necessaril
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10

Robel, Alexander A., Earle Wilson, and Helene Seroussi. "Layered seawater intrusion and melt under grounded ice." Cryosphere 16, no. 2 (2022): 451–69. http://dx.doi.org/10.5194/tc-16-451-2022.

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Abstract. Increasing melt of ice sheets at their floating or vertical interfaces with the ocean is a major driver of marine ice sheet retreat and sea level rise. However, the extent to which warm, salty seawater may drive melting under the grounded portions of ice sheets is still not well understood. Previous work has explored the possibility that dense seawater intrudes beneath relatively light subglacial freshwater discharge, similar to the “salt wedge” observed in many estuarine systems. In this study, we develop a generalized theory of layered seawater intrusion under grounded ice, includi
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11

Leguy, Gunter R., William H. Lipscomb, and Xylar S. Asay-Davis. "Marine ice sheet experiments with the Community Ice Sheet Model." Cryosphere 15, no. 7 (2021): 3229–53. http://dx.doi.org/10.5194/tc-15-3229-2021.

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Abstract. Ice sheet models differ in their numerical treatment of dynamical processes. Simulations of marine-based ice are sensitive to the choice of Stokes flow approximation and basal friction law and to the treatment of stresses and melt rates near the grounding line. We study the effects of these numerical choices on marine ice sheet dynamics in the Community Ice Sheet Model (CISM). In the framework of the Marine Ice Sheet Model Intercomparison Project 3d (MISMIP3d), we show that a depth-integrated, higher-order solver gives results similar to a 3D (Blatter–Pattyn) solver. We confirm that
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12

Marschalek, James W., Edward Gasson, Tina van de Flierdt, Claus-Dieter Hillenbrand, Martin J. Siegert, and Liam Holder. "Quantitative sub-ice and marine tracing of Antarctic sediment provenance (TASP v1.0)." Geoscientific Model Development 18, no. 5 (2025): 1673–708. https://doi.org/10.5194/gmd-18-1673-2025.

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Abstract. Ice sheet models should be able to accurately simulate palaeo ice sheets to have confidence in their projections of future polar ice sheet mass loss and resulting global sea level rise. This requires accurate reconstructions of the extent and flow patterns of palaeo ice sheets using real-world data. Such reconstructions can be achieved by tracing the detrital components of offshore sedimentary records back to their source areas on land. For Antarctica, however, sediment provenance data and ice sheet model results have not been directly linked, despite the complementary information ea
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13

Peyaud, V., C. Ritz, and G. Krinner. "Modelling the Early Weichselian Eurasian Ice Sheets: role of ice shelves and influence of ice-dammed lakes." Climate of the Past 3, no. 3 (2007): 375–86. http://dx.doi.org/10.5194/cp-3-375-2007.

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Abstract. During the last glaciation, a marine ice sheet repeatedly appeared in Eurasia. The floating part of this ice sheet was essential to its rapid extension over the seas. During the earliest stage (90 kyr BP), large ice-dammed lakes formed south of the ice sheet. These lakes are believed to have cooled the climate at the margin of the ice. Using an ice sheet model, we investigated the role of ice shelves during the inception and the influence of ice-dammed lakes on the ice sheet evolution. Inception in Barents sea seems due to thickening of a large ice shelf. We observe a substantial imp
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14

Peyaud, V., C. Ritz, and G. Krinner. "Modelling the Early Weichselian Eurasian Ice Sheets: role of ice shelves and influence of ice-dammed lakes." Climate of the Past Discussions 3, no. 1 (2007): 221–47. http://dx.doi.org/10.5194/cpd-3-221-2007.

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Abstract. During the last glaciation, a marine ice sheet repeatedly appeared in Eurasia. The floating part of this ice sheet was essential to its rapid extension over the seas. During the earliest stage (90 kyr BP), large ice-dammed lakes formed south of the ice sheet. These lakes are believed to have cooled the climate at the margin of the ice. Using an ice sheet model, we investigated the role of ice shelves during the inception and the influence of ice-dammed lakes on the ice sheet evolution. Inception in Barents sea seems due to thickening of a large ice shelf. We observe a substantial imp
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15

Robel, Alexander A., Vincent Verjans, and Aminat A. Ambelorun. "Biases in ice sheet models from missing noise-induced drift." Cryosphere 18, no. 5 (2024): 2613–23. http://dx.doi.org/10.5194/tc-18-2613-2024.

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Abstract. Most climatic and glaciological processes exhibit internal variability, which is omitted from many ice sheet model simulations. Prior studies have found that climatic variability can change ice sheet sensitivity to the long-term mean and trend in climate forcing. In this study, we use an ensemble of simulations with a stochastic large-scale ice sheet model to demonstrate that variability in frontal ablation of marine-terminating glaciers changes the mean state of the Greenland Ice Sheet through noise-induced drift. Conversely, stochastic variability in surface mass balance does not a
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16

Cofaigh, Colm Ó. "Ice sheets viewed from the ocean: the contribution of marine science to understanding modern and past ice sheets." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370, no. 1980 (2012): 5512–39. http://dx.doi.org/10.1098/rsta.2012.0398.

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Over the last two decades, marine science, aided by technological advances in sediment coring, geophysical imaging and remotely operated submersibles, has played a major role in the investigation of contemporary and former ice sheets. Notable advances have been achieved with respect to reconstructing the extent and flow dynamics of the large polar ice sheets and their mid-latitude counterparts during the Quaternary from marine geophysical and geological records of landforms and sediments on glacier-influenced continental margins. Investigations of the deep-sea ice-rafted debris record have dem
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17

Hindmarsh, Richard C. A., and E. Le Meur. "Dynamical processes involved in the retreat of marine ice sheets." Journal of Glaciology 47, no. 157 (2001): 271–82. http://dx.doi.org/10.3189/172756501781832269.

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AbstractMarine ice sheets with mechanics described by the shallow-ice approximation by definition do not couple mechanically with the shelf. Such ice sheets are known to have neutral equilibria. We consider the implications of this for their dynamics and in particular for mechanisms which promote marine ice-sheet retreat. The removal of ice-shelf buttressing leading to enhanced flow in grounded ice is discounted as a significant influence on mechanical grounds. Sea-level rise leading to reduced effective pressures under ice streams is shown to be a feasible mechanism for producing postglacial
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18

Christ, Andrew J., Tammy M. Rittenour, Paul R. Bierman, et al. "Deglaciation of northwestern Greenland during Marine Isotope Stage 11." Science 381, no. 6655 (2023): 330–35. http://dx.doi.org/10.1126/science.ade4248.

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Past interglacial climates with smaller ice sheets offer analogs for ice sheet response to future warming and contributions to sea level rise; however, well-dated geologic records from formerly ice-free areas are rare. Here we report that subglacial sediment from the Camp Century ice core preserves direct evidence that northwestern Greenland was ice free during the Marine Isotope Stage (MIS) 11 interglacial. Luminescence dating shows that sediment just beneath the ice sheet was deposited by flowing water in an ice-free environment 416 ± 38 thousand years ago. Provenance analyses and cosmogenic
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19

Kleman, J., J. Fastook, K. Ebert, J. Nilsson, and R. Caballero. "Pre-LGM Northern Hemisphere ice sheet topography." Climate of the Past 9, no. 5 (2013): 2365–78. http://dx.doi.org/10.5194/cp-9-2365-2013.

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Abstract. We here reconstruct the paleotopography of Northern Hemisphere ice sheets during the glacial maxima of marine isotope stages (MIS) 5b and 4.We employ a combined approach, blending geologically based reconstruction and numerical modeling, to arrive at probable ice sheet extents and topographies for each of these two time slices. For a physically based 3-D calculation based on geologically derived 2-D constraints, we use the University of Maine Ice Sheet Model (UMISM) to calculate ice sheet thickness and topography. The approach and ice sheet modeling strategy is designed to provide ro
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20

Asay-Davis, Xylar S., Stephen L. Cornford, Gaël Durand, et al. "Experimental design for three interrelated marine ice sheet and ocean model intercomparison projects: MISMIP v. 3 (MISMIP +), ISOMIP v. 2 (ISOMIP +) and MISOMIP v. 1 (MISOMIP1)." Geoscientific Model Development 9, no. 7 (2016): 2471–97. http://dx.doi.org/10.5194/gmd-9-2471-2016.

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Abstract. Coupled ice sheet–ocean models capable of simulating moving grounding lines are just becoming available. Such models have a broad range of potential applications in studying the dynamics of marine ice sheets and tidewater glaciers, from process studies to future projections of ice mass loss and sea level rise. The Marine Ice Sheet–Ocean Model Intercomparison Project (MISOMIP) is a community effort aimed at designing and coordinating a series of model intercomparison projects (MIPs) for model evaluation in idealized setups, model verification based on observations, and future projecti
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21

Asay-Davis, X. S., S. L. Cornford, G. Durand, et al. "Experimental design for three interrelated Marine Ice-Sheet and Ocean Model Intercomparison Projects." Geoscientific Model Development Discussions 8, no. 11 (2015): 9859–924. http://dx.doi.org/10.5194/gmdd-8-9859-2015.

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Abstract. Coupled ice sheet-ocean models capable of simulating moving grounding lines are just becoming available. Such models have a broad range of potential applications in studying the dynamics of marine ice sheets and tidewater glaciers, from process studies to future projections of ice mass loss and sea level rise. The Marine Ice Sheet-Ocean Model Intercomparison Project (MISOMIP) is a community effort aimed at designing and coordinating a series of model intercomparison projects (MIPs) for model evaluation in idealized setups, model verification based on observations, and future projecti
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22

McKenzie, Marion A., Lauren E. Miller, Allison P. Lepp, and Regina DeWitt. "Spatial variability of marine-terminating ice sheet retreat in the Puget Lowland." Climate of the Past 20, no. 4 (2024): 891–908. http://dx.doi.org/10.5194/cp-20-891-2024.

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Abstract. Understanding drivers of marine-terminating ice sheet behavior is important for constraining ice contributions to global sea level rise. In part, the stability of marine-terminating ice is influenced by solid Earth conditions at the grounded-ice margin. While the Cordilleran Ice Sheet (CIS) contributed significantly to global mean sea level during its final post-Last-Glacial-Maximum (LGM) collapse, the drivers and patterns of retreat are not well constrained. Coastal outcrops in the deglaciated Puget Lowland of Washington State – largely below sea level during glacial maxima, then up
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23

Sun, Sainan, Frank Pattyn, Erika G. Simon, et al. "Antarctic ice sheet response to sudden and sustained ice-shelf collapse (ABUMIP)." Journal of Glaciology 66, no. 260 (2020): 891–904. http://dx.doi.org/10.1017/jog.2020.67.

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AbstractAntarctica's ice shelves modulate the grounded ice flow, and weakening of ice shelves due to climate forcing will decrease their ‘buttressing’ effect, causing a response in the grounded ice. While the processes governing ice-shelf weakening are complex, uncertainties in the response of the grounded ice sheet are also difficult to assess. The Antarctic BUttressing Model Intercomparison Project (ABUMIP) compares ice-sheet model responses to decrease in buttressing by investigating the ‘end-member’ scenario of total and sustained loss of ice shelves. Although unrealistic, this scenario en
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24

Zhang, Zhe. "Reviewing the elements of marine ice cliff instability." Journal of Physics: Conference Series 2152, no. 1 (2022): 012057. http://dx.doi.org/10.1088/1742-6596/2152/1/012057.

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Abstract Antarctica’s ice sheets are the largest potential sea-level rise contributors, but projections of future sea-level rise yield wide ranges of estimates under different emission scenarios. An important factor in the variability of estimates is marine ice cliff instability (MICI). Inclusion of MICI yields the highest potential sea-level rise cases but also the largest uncertainty due to poor understanding of the factors that control it and the mechanisms of how it happens. Although evidence for MICI has been implied by paleo-ice sheet studies and observations of keel plough mark on sea-f
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25

Kleman, J., J. Fastook, K. Ebert, J. Nilsson, and R. Caballero. "Pre-LGM Northern Hemisphere paleo-ice sheet topography." Climate of the Past Discussions 9, no. 3 (2013): 2557–87. http://dx.doi.org/10.5194/cpd-9-2557-2013.

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Abstract. We here reconstruct the paleotopgraphy of Northern Hemisphere ice sheets during the glacial maxima of marine isotope stages (MIS) 5b and 4. We employ two approaches, geologically based reconstruction and numerical modeling, in mutually supportive roles to arrive at probable ice sheet extents and topographies for each of these two time slices. For a physically based 3-D calculation based on geologically derived 2-D constraints, we use the University of Maine Ice Sheet Model (UMISM) to calculate ice-sheet thickness and topography. The approach and ice-sheet modeling strategy is designe
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26

Favier, Lionel, Frank Pattyn, Sophie Berger, and Reinhard Drews. "Dynamic influence of pinning points on marine ice-sheet stability: a numerical study in Dronning Maud Land, East Antarctica." Cryosphere 10, no. 6 (2016): 2623–35. http://dx.doi.org/10.5194/tc-10-2623-2016.

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Abstract. The East Antarctic ice sheet is likely more stable than its West Antarctic counterpart because its bed is largely lying above sea level. However, the ice sheet in Dronning Maud Land, East Antarctica, contains marine sectors that are in contact with the ocean through overdeepened marine basins interspersed by grounded ice promontories and ice rises, pinning and stabilising the ice shelves. In this paper, we use the ice-sheet model BISICLES to investigate the effect of sub-ice-shelf melting, using a series of scenarios compliant with current values, on the ice-dynamic stability of the
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27

Drouet, A. S., D. Docquier, G. Durand, et al. "Grounding line transient response in marine ice sheet models." Cryosphere Discussions 6, no. 5 (2012): 3903–35. http://dx.doi.org/10.5194/tcd-6-3903-2012.

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Abstract. Marine ice sheet stability is mostly controlled by the dynamics of the grounding line, i.e., the junction between the grounded ice sheet and the floating ice shelf. Grounding line migration has been investigated in the framework of MISMIP (Marine Ice Sheet Model Intercomparison Project), which mainly aimed at investigating steady state solutions. Here we focus on transient behaviour, executing short-term simulations (200 yr) of a steady ice sheet perturbed by the release of the buttressing restraint exerted by the ice shelf on the grounded ice upstream. The transient grounding line b
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28

SCHOOF, CHRISTIAN. "Marine ice-sheet dynamics. Part 1. The case of rapid sliding." Journal of Fluid Mechanics 573 (February 2007): 27–55. http://dx.doi.org/10.1017/s0022112006003570.

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Marine ice sheets are continental ice masses resting on bedrock below sea level. Their dynamics are similar to those of land-based ice sheets except that they must couple with the surrounding floating ice shelves at the grounding line, where the ice reaches a critical flotation thickness. In order to predict the evolution of the grounding line as a free boundary, two boundary conditions are required for the diffusion equation describing the evolution of the grounded-ice thickness. By analogy with Stefan problems, one of these conditions imposes a prescribed ice thickness at the grounding line
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29

Mas e Braga, Martim, Jorge Bernales, Matthias Prange, Arjen P. Stroeven, and Irina Rogozhina. "Sensitivity of the Antarctic ice sheets to the warming of marine isotope substage 11c." Cryosphere 15, no. 1 (2021): 459–78. http://dx.doi.org/10.5194/tc-15-459-2021.

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Abstract. Studying the response of the Antarctic ice sheets during periods when climate conditions were similar to the present can provide important insights into current observed changes and help identify natural drivers of ice sheet retreat. In this context, the marine isotope substage 11c (MIS11c) interglacial offers a suitable scenario, given that during its later portion orbital parameters were close to our current interglacial. Ice core data indicate that warmer-than-present temperatures lasted for longer than during other interglacials. However, the response of the Antarctic ice sheets
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30

Sergienko, O. V., and D. J. Wingham. "Grounding line stability in a regime of low driving and basal stresses." Journal of Glaciology 65, no. 253 (2019): 833–49. http://dx.doi.org/10.1017/jog.2019.53.

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AbstractThe dynamics of a marine ice sheet's grounding lines determine the rate of ice discharge from the grounded part of ice sheet into surrounding oceans. In many locations in West Antarctica ice flows into ice shelves through ice streams experiencing low driving stress. However, existing simple theories of marine ice sheets are developed under the assumption of high basal and driving stress. Here we analyze the grounding line behavior of marine ice streams experiencing low basal shear and driving stress. We find that in this regime, the ice flux at the grounding line is a complex function
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31

van Dongen, Eef C. H., Nina Kirchner, Martin B. van Gijzen, et al. "Dynamically coupling full Stokes and shallow shelf approximation for marine ice sheet flow using Elmer/Ice (v8.3)." Geoscientific Model Development 11, no. 11 (2018): 4563–76. http://dx.doi.org/10.5194/gmd-11-4563-2018.

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Abstract. Ice flow forced by gravity is governed by the full Stokes (FS) equations, which are computationally expensive to solve due to the nonlinearity introduced by the rheology. Therefore, approximations to the FS equations are commonly used, especially when modeling a marine ice sheet (ice sheet, ice shelf, and/or ice stream) for 103 years or longer. The shallow ice approximation (SIA) and shallow shelf approximation (SSA) are commonly used but are accurate only for certain parts of an ice sheet. Here, we report a novel way of iteratively coupling FS and SSA that has been implemented in El
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32

Pollard, Oliver G., Natasha L. M. Barlow, Lauren J. Gregoire, et al. "Quantifying the uncertainty in the Eurasian ice-sheet geometry at the Penultimate Glacial Maximum (Marine Isotope Stage 6)." Cryosphere 17, no. 11 (2023): 4751–77. http://dx.doi.org/10.5194/tc-17-4751-2023.

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Abstract. The North Sea Last Interglacial sea level is sensitive to the fingerprint of mass loss from polar ice sheets. However, the signal is complicated by the influence of glacial isostatic adjustment driven by Penultimate Glacial Period ice-sheet changes, and yet these ice-sheet geometries remain significantly uncertain. Here, we produce new reconstructions of the Eurasian ice sheet during the Penultimate Glacial Maximum (PGM) by employing large ensemble experiments from a simple ice-sheet model that depends solely on basal shear stress, ice extent, and topography. To explore the range of
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33

Van der Veen, C. J. "Response of a Marine Ice Sheet to Changes at the Grounding Line." Quaternary Research 24, no. 3 (1985): 257–67. http://dx.doi.org/10.1016/0033-5894(85)90049-3.

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A numerical model was designed to study the stability of a marine ice sheet, and used to do some basic experiments. The ice-shelf/ice-sheet interaction enters through the flow law in which the longitudinal stress is also taken into account. Instead of applying the model to some (measured) profile and showing that this is unstable (as is common practice in other studies), an attempt is made to simulate a whole cycle of growth and retreat of a marine ice sheet, although none of the model sheets is particularly sensitive to changes in environmental conditions. The question as to what might happen
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34

Drouet, A. S., D. Docquier, G. Durand, et al. "Grounding line transient response in marine ice sheet models." Cryosphere 7, no. 2 (2013): 395–406. http://dx.doi.org/10.5194/tc-7-395-2013.

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Abstract. Marine ice-sheet stability is mostly controlled by the dynamics of the grounding line, i.e. the junction between the grounded ice sheet and the floating ice shelf. Grounding line migration has been investigated within the framework of MISMIP (Marine Ice Sheet Model Intercomparison Project), which mainly aimed at investigating steady state solutions. Here we focus on transient behaviour, executing short-term simulations (200 yr) of a steady ice sheet perturbed by the release of the buttressing restraint exerted by the ice shelf on the grounded ice upstream. The transient grounding lin
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35

Berg, Sonja, Bernd Wagner, Duanne A. White, and Martin Melles. "No significant ice-sheet expansion beyond present ice margins during the past 4500 yr at Rauer Group, East Antarctica." Quaternary Research 74, no. 1 (2010): 23–25. http://dx.doi.org/10.1016/j.yqres.2010.04.004.

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AbstractThe history of glacial advances and retreats of the East Antarctic ice sheet during the Holocene is not well-known, due to limited field evidence in both the marine and terrestrial realm. A 257-cm-long sediment core was recovered from a marine inlet in the Rauer Group, East Antarctica, 1.8 km in front of the present ice-sheet margin. Radiocarbon dating and lithological characteristics reveal that the core comprises a complete marine record since 4500 yr. A significant ice-sheet expansion beyond present ice margins therefore did not occur during this period.
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36

Halberstadt, Anna Ruth W., Greg Balco, Hannah Buchband, and Perry Spector. "Cosmogenic-nuclide data from Antarctic nunataks can constrain past ice sheet instabilities." Cryosphere 17, no. 4 (2023): 1623–43. http://dx.doi.org/10.5194/tc-17-1623-2023.

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Abstract. We apply geologic evidence from ice-free areas in Antarctica to evaluate model simulations of ice sheet response to warm climates. This is important because such simulations are used to predict ice sheet behaviour in future warm climates, but geologic evidence of smaller-than-present past ice sheets is buried under the present ice sheet and therefore generally unavailable for model benchmarking. We leverage an alternative accessible geologic dataset for this purpose: cosmogenic-nuclide concentrations in bedrock surfaces of interior nunataks. These data produce a frequency distributio
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37

Matero, Ilkka S. O., Lauren J. Gregoire, and Ruza F. Ivanovic. "Simulating the Early Holocene demise of the Laurentide Ice Sheet with BISICLES (public trunk revision 3298)." Geoscientific Model Development 13, no. 9 (2020): 4555–77. http://dx.doi.org/10.5194/gmd-13-4555-2020.

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Abstract. Simulating the demise of the Laurentide Ice Sheet covering Hudson Bay in the Early Holocene (10–7 ka) is important for understanding the role of accelerated changes in ice sheet topography and melt in the 8.2 ka event, a century long cooling of the Northern Hemisphere by several degrees. Freshwater released from the ice sheet through a surface mass balance instability (known as the saddle collapse) has been suggested as a major forcing for the 8.2 ka event, but the temporal evolution of this pulse has not been constrained. Dynamical ice loss and marine interactions could have signifi
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38

Marshall, Shawn J., Lev Tarasov, Garry K. C. Clarke, and W. Richard Peltier. "Glaciological reconstruction of the Laurentide Ice Sheet: physical processes and modelling challenges." Canadian Journal of Earth Sciences 37, no. 5 (2000): 769–93. http://dx.doi.org/10.1139/e99-113.

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Current understanding of Pleistocene ice-sheet history is based on collective inferences from three separate avenues of study: (1) the geologic and paleoceanographic records, (2) the isostatic record, and (3) the behaviour of contemporary glaciers and ice sheets. The geologic record provides good constraint on the areal extent of former ice sheets, while isostatic deflection patterns provide important information about late-glacial ice-sheet thickness. The picture emerging from geologic and isostatic deductions is suggestive of a thin and mobile Laurentide Ice Sheet relative to present-day Gre
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39

Patton, H., A. Hubbard, T. Bradwell, N. F. Glasser, M. J. Hambrey, and C. D. Clark. "Rapid marine deglaciation: asynchronous retreat dynamics between the Irish Sea Ice Stream and terrestrial outlet glaciers." Earth Surface Dynamics Discussions 1, no. 1 (2013): 277–309. http://dx.doi.org/10.5194/esurfd-1-277-2013.

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Abstract. Understanding the retreat behaviour of past marine-ice sheets provides vital context to accurate assessment of the present stability and long-term response of contemporary polar-ice sheets to climate and oceanic warming. Here new multibeam swath-bathymetry data and sedimentological analysis are combined with high resolution ice-sheet modelling to reveal complex landform assemblages and process-dynamics associated with deglaciation of the British-Celtic Ice Sheet (BCIS) within the Irish Sea Basin. Our reconstruction indicates a non-linear relationship between the rapidly receding Iris
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40

Kaplan, Michael R., W. Tad Pfeffer, Christophe Sassolas, and Gifford H. Miller. "Numerical modelling of the Laurentide Ice Sheet in the Baffin Island region: the role of a Cumberland Sound ice stream." Canadian Journal of Earth Sciences 36, no. 8 (1999): 1315–26. http://dx.doi.org/10.1139/e99-027.

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A numerical model reconstruction was made of the northeastern Laurentide Ice Sheet in the Baffin Island - Foxe Basin region using geophysical, terrestrial, and marine geologic evidence for initial and boundary conditions. The simulated ice sheet consists of a Foxe Dome with additional smaller Hall and Amadjuak domes and a Penny Ice Divide. A specific objective was to determine boundary conditions that would allow advance of a marine-based low surface slope ice stream into and out of Cumberland Sound, a major marine embayment in the uplifted rim of the eastern Canadian Arctic (up to 1200 m deep
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41

Choudhury, Dipayan, Axel Timmermann, Fabian Schloesser, Malte Heinemann, and David Pollard. "Simulating Marine Isotope Stage 7 with a coupled climate–ice sheet model." Climate of the Past 16, no. 6 (2020): 2183–201. http://dx.doi.org/10.5194/cp-16-2183-2020.

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Abstract. It is widely accepted that orbital variations are responsible for the generation of glacial cycles during the late Pleistocene. However, the relative contributions of the orbital forcing compared to CO2 variations and other feedback mechanisms causing the waxing and waning of ice sheets have not been fully understood. Testing theories of ice ages beyond statistical inferences, requires numerical modeling experiments that capture key features of glacial transitions. Here, we focus on the glacial buildup from Marine Isotope Stage (MIS) 7 to 6 covering the period from 240 to 170 ka (ka:
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42

Blasco, Javier, Ilaria Tabone, Jorge Alvarez-Solas, Alexander Robinson, and Marisa Montoya. "The Antarctic Ice Sheet response to glacial millennial-scale variability." Climate of the Past 15, no. 1 (2019): 121–33. http://dx.doi.org/10.5194/cp-15-121-2019.

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Abstract. The Antarctic Ice Sheet (AIS) is the largest ice sheet on Earth and hence a major potential contributor to future global sea-level rise. A wealth of studies suggest that increasing oceanic temperatures could cause a collapse of its marine-based western sector, the West Antarctic Ice Sheet, through the mechanism of marine ice-sheet instability, leading to a sea-level increase of 3–5 m. Thus, it is crucial to constrain the sensitivity of the AIS to rapid climate changes. The last glacial period is an ideal benchmark period for this purpose as it was punctuated by abrupt Dansgaard–Oesch
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43

Lu, George, and Jonathan Kingslake. "Two-way coupling between ice flow and channelized subglacial drainage enhances modeled marine-ice-sheet retreat." Cryosphere 18, no. 11 (2024): 5301–21. http://dx.doi.org/10.5194/tc-18-5301-2024.

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Abstract. Ice-sheet models used to predict sea-level rise often neglect subglacial hydrology. However, theory and observations suggest that ice flow and subglacial water flow are bidirectionally coupled: ice geometry affects hydraulic potential, hydraulic potential modulates basal shear stress via the basal water pressure, and ice flow advects the subglacial drainage system. This coupling could impact rates of ice mass change but remains poorly understood. We develop a coupled ice–subglacial-hydrology model to investigate the effects of coupling on the long-term evolution of marine-terminating
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44

Fogwill, C. J., C. S. M. Turney, N. R. Golledge, et al. "Drivers of abrupt Holocene shifts in West Antarctic ice stream direction determined from combined ice sheet modelling and geologic signatures." Antarctic Science 26, no. 6 (2014): 674–86. http://dx.doi.org/10.1017/s0954102014000613.

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AbstractDetermining the millennial-scale behaviour of marine-based sectors of the West Antarctic Ice Sheet (WAIS) is critical to improve predictions of the future contribution of Antarctica to sea level rise. Here high-resolution ice sheet modelling was combined with new terrestrial geological constraints (in situ14C and 10Be analysis) to reconstruct the evolution of two major ice streams entering the Weddell Sea over 20 000 years. The results demonstrate how marked differences in ice flux at the marine margin of the expanded Antarctic ice sheet led to a major reorganization of ice streams in
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Hinck, Sebastian, Evan J. Gowan, Xu Zhang, and Gerrit Lohmann. "PISM-LakeCC: Implementing an adaptive proglacial lake boundary in an ice sheet model." Cryosphere 16, no. 3 (2022): 941–65. http://dx.doi.org/10.5194/tc-16-941-2022.

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Abstract. During the Late Pleistocene and Holocene retreat of paleo-ice sheets in North America and Europe, vast proglacial lakes existed along the land terminating margins. These proglacial lakes impacted ice sheet dynamics by imposing boundary conditions analogous to a marine terminating margin. Such lacustrine boundary conditions cause changes in the ice sheet geometry, stress balance and frontal ablation and therefore affect the mass balance of the entire ice sheet. Despite this, dynamically evolving proglacial lakes have rarely been considered in detail in ice sheet modeling endeavors. In
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Robel, Alexander A., Hélène Seroussi, and Gerard H. Roe. "Marine ice sheet instability amplifies and skews uncertainty in projections of future sea-level rise." Proceedings of the National Academy of Sciences 116, no. 30 (2019): 14887–92. http://dx.doi.org/10.1073/pnas.1904822116.

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Sea-level rise may accelerate significantly if marine ice sheets become unstable. If such instability occurs, there would be considerable uncertainty in future sea-level rise projections due to imperfectly modeled ice sheet processes and unpredictable climate variability. In this study, we use mathematical and computational approaches to identify the ice sheet processes that drive uncertainty in sea-level projections. Using stochastic perturbation theory from statistical physics as a tool, we show mathematically that the marine ice sheet instability greatly amplifies and skews uncertainty in s
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47

Patton, H., A. Hubbard, T. Bradwell, N. F. Glasser, M. J. Hambrey, and C. D. Clark. "Rapid marine deglaciation: asynchronous retreat dynamics between the Irish Sea Ice Stream and terrestrial outlet glaciers." Earth Surface Dynamics 1, no. 1 (2013): 53–65. http://dx.doi.org/10.5194/esurf-1-53-2013.

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Abstract. Understanding the retreat behaviour of past marine-based ice sheets provides vital context for accurate assessments of the present stability and long-term response of contemporary polar ice sheets to climate and oceanic warming. Here new multibeam swath bathymetry data and sedimentological analysis are combined with high resolution ice-sheet modelling to reveal complex landform assemblages and process dynamics associated with deglaciation of the Celtic ice sheet within the Irish Sea Basin. Our reconstruction indicates a non-linear relationship between the rapidly receding Irish Sea I
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48

Goelzer, Heiko, Violaine Coulon, Frank Pattyn, Bas de Boer, and Roderik van de Wal. "Brief communication: On calculating the sea-level contribution in marine ice-sheet models." Cryosphere 14, no. 3 (2020): 833–40. http://dx.doi.org/10.5194/tc-14-833-2020.

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Abstract. Estimating the contribution of marine ice sheets to sea-level rise is complicated by ice grounded below sea level that is replaced by ocean water when melted. The common approach is to only consider the ice volume above floatation, defined as the volume of ice to be removed from an ice column to become afloat. With isostatic adjustment of the bedrock and external sea-level forcing that is not a result of mass changes of the ice sheet under consideration, this approach breaks down, because ice volume above floatation can be modified without actual changes in the sea-level contribution
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49

Jong, Lenneke M., Rupert M. Gladstone, Benjamin K. Galton-Fenzi, and Matt A. King. "Simulated dynamic regrounding during marine ice sheet retreat." Cryosphere 12, no. 7 (2018): 2425–36. http://dx.doi.org/10.5194/tc-12-2425-2018.

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Abstract. Marine-terminating ice sheets are of interest due to their potential instability, making them vulnerable to rapid retreat. Modelling the evolution of glaciers and ice streams in such regions is key to understanding their possible contribution to sea level rise. The friction caused by the sliding of ice over bedrock and the resultant shear stress are important factors in determining the velocity of sliding ice. Many models use simple power-law expressions for the relationship between the basal shear stress and ice velocity or introduce an effective-pressure dependence into the sliding
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50

Liakka, J., M. Löfverström, and F. Colleoni. "The impact of the North American ice sheet on the evolution of the Eurasian ice sheet during the last glacial cycle." Climate of the Past Discussions 11, no. 6 (2015): 5203–41. http://dx.doi.org/10.5194/cpd-11-5203-2015.

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Abstract. Modeling studies show that the massive ice sheet expanding over the North American and Eurasian continents in the last glacial cycle has a large impact on the atmospheric stationary waves and thus yielded a glacial climate distinctly different from the present. However, to what extent the two ice sheets influenced each others growth trajectories remains largely unexplored. In this study we investigate how ice sheets in North America influence the downstream evolution of the Eurasian ice sheet, using a thermomechanical ice-sheet model forced by climate data from snapshot simulations o
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